we welcome president barack obama and governor mitt romney. gentlemen, your campaigns have agreed to certain rules and they are simple. they have asked me to divide the evening into segments. i'll pose a question at the beginning of each segment. you will each have two minutes to respond, and then we will have a general discussion until we move to the next segment. tonight's debate, as both of your know, comes on the 50th anniversary of the night that president kennedy told the world that the soviet union had installed nuclear missiles in cuba -- perhaps the closest we've ever come to nuclear war. and it is a sobering reminder that every president faces at some point an unexpected threat to our national security from abroad. so let's begin. the first segment is the challenge of a changing middle east and the new face of terrorism. i'm going to put this into two segments, so you'll have two topic questions within this one segment on that subject. the first question, and it concerns libya, the controversy over what happened there continues. four